Wang Li-Xiao, Chen Hui, Lin Rui-Tian, Gu Li-Sha
Hospital of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China.
Guangdong Provincial Key Laboratory of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China.
J Dent Sci. 2022 Jul;17(3):1274-1280. doi: 10.1016/j.jds.2021.11.012. Epub 2021 Dec 6.
BACKGROUND/PURPOSE: There is no consensus to date on how many repetitive pecking motions at working length (WL) should be regarded as optimal during instrumentation. Therefore, this study aimed to evaluate the effect of pecking frequency at WL on the volume of apically extruded debris using three single-file systems in curved, oval-shaped canals.
Forty-five single-rooted mandibular premolars with curved, oval-shaped canals were prescanned by micro-computed tomography, anatomically paired-matched, and randomly divided among three groups (n = 15 each): Reciproc Blue (RB), WaveOne Gold (WOG) and XP-endo Shaper (XPS). Samples were embedded in agarose gel to collect extruded debris. After preparation to the WL, each sample was rescanned after one, two, four, 10, and 20 pecking motions at WL, respectively. The debris volume was innovatively calculated by a modification of an existing method using micro-computed tomography. The apical preparation size was also measured. Data were compared using a two-way repeated-measures analysis of variance.
All single-file systems extruded debris apically, irrespective of the pecking frequency at WL. The extruded debris volume correlated positively with the minor foramen size ( < 0.05); both increased with pecking frequency for each single-file system ( < 0.05). The minor foramen size corresponded to the instrument tip size when reaching the WL once.
To produce less debris extrusion and obtain a predictable foramen size corresponding to the instrument tip size, a single pecking motion may be preferred when using single-file systems. Caution should be exercised when applying the current results to clinical situations.
背景/目的：迄今为止，对于在根管预备过程中工作长度（WL）处进行多少次重复啄击运动应被视为最佳次数尚无共识。因此，本研究旨在使用三种单根管器械系统，评估在弯曲的椭圆形根管中，WL处的啄击频率对根尖部挤出碎屑量的影响。
对45颗具有弯曲椭圆形根管的单根下颌前磨牙进行显微计算机断层扫描预扫描，进行解剖学配对匹配，然后随机分为三组（每组n = 15）：Reciproc Blue（RB）、WaveOne Gold（WOG）和XP-endo Shaper（XPS）。将样本嵌入琼脂糖凝胶中以收集挤出的碎屑。在预备至WL后，分别在WL处进行1次、2次、4次、10次和20次啄击运动后，对每个样本再次进行扫描。通过对现有方法进行修改，利用显微计算机断层扫描创新性地计算碎屑体积。同时测量根尖预备尺寸。使用双向重复测量方差分析比较数据。
所有单根管器械系统均会向根尖部挤出碎屑，与WL处的啄击频率无关。挤出的碎屑体积与根尖孔大小呈正相关（P < 0.05）；对于每个单根管器械系统，两者均随啄击频率增加而增加（P < 0.05）。当器械一次到达WL时，根尖孔大小与器械尖端尺寸相对应。
为了减少碎屑挤出并获得与器械尖端尺寸相对应的可预测的根尖孔大小，在使用单根管器械系统时，单次啄击运动可能更为可取。将当前结果应用于临床情况时应谨慎。
